In recent years attention has focused on organic electroluminescent light emitting devices for applications such as plane light sources and the like. In an organic electroluminescent light emitting device, an organic thin film is provided between a cathode and an anode. By applying a voltage to the organic thin film, electrons are injected from the cathode, electron holes are injected from the anode, and excitons are generated by causing recombination. The light emitted when the excitons radiatively deactivate is used.
In organic electroluminescent light emitting devices, it is desirable to improve the light extraction efficiency.